Umar Bhai!
In my opinion, this gathering must take place, even if it turns out to be a meeting of a few members only. Because It will help introduce the forum members to each other as well as to the moderators available at the gathering.
For making the arrangement and knowing the anticipated number of participants, you may announce the date, time & venue of the gathering and ask the forum members to confirm their availability for the occasion, at least 24 hours before the gathering time. I am sure, response would be much better this time, compared to the previous one.
Moreover, a WhatsApp group may also be created, in order to develop direct communication between the Forum members.
Regards.